<PRE><B>Question 305480</B>
Given 2 points example. 
Find the equation of the line thru the points (2,1) and (3,5)
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This is a 2 step process.  First find the slope of the line thru the points.
slope, m = diffy/diffx
m = (5-1)/(3-2)
m = 4
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Now use y = mx + b with either point to find b, the y-intercept.
y = mx + b
5 = 4*3 + b
b = -7
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y = mx + b
y = 4x - 7 is the answer.
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Another approach using determinants:
|x y 1|
|2 1 1| = 0
|3 5 1|
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x(1-5) - y(2-3) + 1(10-3) = 0
-4x + y + 7 = 0
y = 4x - 7
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For further assistance, or to check your work, email me via the thank you note 
 or at Moral Loophole@aol.com
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